Humidifier

ABSTRACT

A device for controllably increasing the relative vapor content, particularly the humidity of a gas comprising, a body having a chamber with a sump in the lower portion, means for admitting fluid opening into said sump, disc means in said chamber rotatable with a sector of its marginal edge in said sump, means for rotating said disc at a speed which is sufficiently high to nebulize fluid within said chamber by the agitating action of the rotating disc member so as to increase the relative humidity of a gas passing through the chamber, inlet means opening into said chamber for admitting gas to said chamber and outlet means opening out of said chamber for withdrawing gas therefrom, said inlet and outlet means being disposed on opposite sides of said disc member.

United States Patent [191 Urbanowicz 1 Jan. 16,1973

1541 HUMIDIFIER [76] Inventor: Nikodem N. Urbanowicz, 151 Albion Street,Brantford, Ontario, Canada [63] Continuation-impart of Ser. No. 59,487,July 30,

1970, abandoned;

2,099,667 11/1937 Howse et a1. ..261/90 3,353,337 11/1967 Gale ..261/922,243,839 6/1941 Dalton .....261/92 2,471,724 5/1949 Christensen..261/92 Primary Examiner--Tim R. Miles Assistant Examiner-Steven H.Markowitz Attorney-Philip T. Mitches [57] ABSTRACT A device forcontrollably increasing the relative vaporcontent, particularly thehumidity of a gas comprising, a body having a chamber with a sump in thelower portion, means for admitting fluid opening into said sump, discmeans in said chamber rotatable with a sector of its marginal edge insaid sump, means for rotating said disc at a speed which is sufficientlyhigh to nebu 1ize fluid within said chamber by the agitating action ofthe rotating disc member so as to increase the relative humidity of agas passing through the chamber, inlet means opening into said chamberfor admitting gas to said chamber and outlet means opening out of saidchamber for withdrawing gas therefrom, said inlet and outlet means beingdisposed on opposite sides of said disc member.

13 Claims, 14 Drawing Figures PATENIEDJAH 16 1975 3,711,071

sum 2 OF 6 igma ATTORNEYS PATENTEDJAH 16 4973 SHEET 3 [1F 6 I N VEN'TUR.

NIKOOEM M uEBA/VoN/cZ.

ATTORNEYS sum 0r 6 m N ukamvow/rz ATTORNEYS PATENTEDJAN 16 19153.711.071

sum 5 or e INVENTOR.

MK QEM M AIRBANONICZ ATTORNEYS HUMIDIFIER CROSS REFERENCE TO RELATEDAPPLICATION This application is a continuation-in-part of applicationSer. No. 59,487, filed July 30, 1970, now abandoned.

This invention relates to a device for controllably increasing the vaporcontent of a gas. In particular, this invention relates to a devicewhich is particularly suitable for increasing the relative, humidity ofanaesthesia gases to prevent dehydration of a patient under ananaesthetic.

PRIOR ART When anaesthesia gases are given to a patient undergoingmedical treatment, it is found that the patients lungs and other organsbecome dehydrated. This dehydration can seriously affect the health ofthe patient and the conventional practice is to attempt to correct thisproblem by intravenous injections. The dehydration of the patientresults from the fact that the anaesthetic gases do not contain themoisture present in the normal atmosphere. To date, no devices have beendeveloped which are capable of controlling the increase in relativehumidity of the anaesthesia gases while they are being administered. Thedifficulties arising in attempting to provide a device for increasingthe relative humidity are that it must be capable of increasing thehumidity very quickly so as to be effective while the gases are beingadministered and in addition, the device must be capable of operatingwithout producing any restriction in the flow of a gas to a patient. Forexample, any device which creates any substantial amount of backpressure would not be acceptable as this would make it difficult for apatient to receive a rapidly increased (accelerated) flow of anaestheticon demand. The amount of moisture which may be required in anaesthesiagases may vary depending upon the requirements of a particular patientand, as a result, it is necessary to provide a device capable ofcontrolling the relative humidity of a gas and, for the reasonsdescribed above, it must be possible to control the relative humidity ofthe gas over a range of supply volumes.

The problem of increasing the vapor content ofa gas or air is one whichis encountered in many fields other than the one described above. Forexample, there are many industrial applications such as vaporization offuels, the curing of tobacco,.water washing and humidifying ventilatingair and chemical spraying in which large volumes of air may be processedand in which large droplet sizes are acceptable. Conventional vaporizerssuch as domestic vaporizers rely exclusively on evaporation. In oneknown structure a drum which is covered with an absorbent material isadapted to rotate in the air intake of a domestic furnace. Thehumidifying action which takes place is the direct result of theevaporation of the moisture from the surface of the drum, in that, itrelies to a large extent upon the fact that the air is drawn rapidlyover the moist surface of the drum. This type of apparatus is notcapable of increasing the relative humidity of the air very rapidly andit relies upon the fact that in domestic applications the air isrecirculated numerous times to step up the humidity in each pass. Thistype of gradual increase in humidity is not suitable for many industrialapplications.

SUMMARY OF INVENTION stipulated by clinical requirements. The apparatusis also capable of introducing anaesthetics or other medicaments into agas stream either alone or together with water.

The present invention overcomes the difficulties of the prior artdescribed above by providing a device for controllably increasing therelative humidity of a gas. The device comprises a body having a chamberand a disc member mounted for rotation in the chamber. The device alsohas means for admitting fluid such as water to the chamber and inlet andoutlet means whereby a gas may pass through the chamber. The disc memberhas means for rotating it within the chamber at a speed which issufficiently high to nebulize the fluid (water) within the chamber bythe agitating action of a rotating disc member to thereby impart fluidvapor (water) to the gas passing through the chamber to increase thevapor content (relative humidity) of the gas.

PREFERRED EMBODIMENT The invention will now be described by way ofexample reference being had to the accompanying drawings in which FIG. 1is a pictorial view of a device according to an embodiment of thepresent invention;

FIG. 2 is a cross-sectional view of the device of FIG. 1 showing a pairof discs mounted for rotation within its chamber.

FIG. 2a is another embodiment of FIG. 2 including fixed baffles.

FIG. 3 is a pictorial view of a pair of discs and the inlet and outletpassages of the chamber illustrating a typical flow path for I a gaspassing through the chamber;

FIG. 4 is a diagrammatic illustration of an anaesthetic circuitillustrating the manner in which the device of the present invention maybe used in anaesthetic applications.

FIG. 5 is a diagrammatic illustration of a valve for proportionallycontrolling the amount of gas passing through the device of FIG. 1.

FIG. 6 is a partially sectioned pictorial view of an alternative form ofdisc; and

FIGS. 7 to 12 inclusive are plan views illustrating alternative discconstruction.

FIG. 13 is a cross-sectional view of FIG. 2a.

Referring to FIG. 1 of the drawings, the reference numeral 10 refersgenerally to a device (nebulizer) for controllably increasing therelative humidity of a gas according to an embodiment of the presentinvention. The device 10 comprises a housing 12, a frame 14, and a motor16. The frame 14 consists of a horizontal platform 18 which has anupright flange 20 at the front end thereof and an archshaped support bar22 at the rear end thereof. Flange 20 and arch support 22 serve tosupport the motor 16. The motor 16 is secured at the front end to theflange 20 by set screws 24.

The motor 16 is preferably a variable speed motor so that the nebulizingconditions prevailing within the chamber 12 may be adjusted by adjustingthe speed of rotation of the motor as will be described hereinafter.

The housing 12 consists of a cylindrical shaped wall 26 and oppositelydisposed disc-shaped side walls 28 and 30. An input vapor trap 32 ismounted on the wall 30 and an output vapor trap 34 is mounted on thewall 28. The wall 30 has a passageway 36 communicating with the vaportrap 32 and the wall 28 has a passageway 38 communicating with the vaportrap 34. An input passage 40 is formed in the side wall of the trap 32and an output passage 42 is formed on the end wall of the trap 34. Itwill be noted that the input passage 40 to and output passage 42 fromchamber 44 are located at a higher level than are the passages 36 and 38formed in the side walls 30 and 28, respectively, of the housing 12. Bymeans of this arrangement of the vapor traps 32 and 34 and of the inputand output passages 36 and 38, it is possible to ensure that liquid willnot be transmitted from the chamber 44 in either (forward or rearward)direction except when it is nebulized into sufficiently fine particlesto be carried by the gas as will become apparent. The lower edge of thehousing 12 may be supported by a platform 18 and the housing is adaptedto be mounted to prevent rotation by being secured to arms 21 (only oneof which is shown in FIG. 1) which extend upwardly from the base plate18 and are secured to the upright support 20.

The frame 14, housing 12 and vapor traps 32, 34 may be formed from anysuitable material such as plastic (polyethylene) or the like or they maybe formed from a metal suitably protected against corrosion.

It will be seen from the foregoing description that the chamber 44 whichis encompased within the housing 12 is generally cylindricallyshaped-When the demand on the device is very high, chamber 44 may befilled with a substantial amount of liquid with the result that thelower portion of the chamber may and shall be referred to hereinafter assump 46.

The drive shaft 48 which extends from 'the electric motor is connectedby a suitable coupling 50 to the main drive shaft 52. As shown in FIG. 2of the drawings, the main drive shaft 52 is mounted for rotation in theside walls 28 and 30 of the housing 12. The shaft is suitably sealedrelative to the walls 28 and 30 to prevent liquid from leaking out ofthe housing. A pair of discs 56 are mounted on the shaft 52 for rotationtherewith. The discs 50 are spaced apart on the shaft by coil spring 58.As will be apparent hereinafter, the discs are suitably constructed tonebulize the water within the chamber by their agitating action whenthey are rotated at high speed. FIG. 2 also serves to diagrammaticallyillustrate a body of water 60 located in the sump 46 of the housing.FIG. 2 also illustrates the location of the water input passage 62. Itwill be noted that this passage is arranged so as to discharge waterinto the chamber in close proximity to the disc 56. This ensures thatwater entering the chamber through feeding tube 64 will strike the blade56 and this serves to further speed the nebulizing of the water when theblade 56 is rotating.

A typical flow path for the gas through the chamber 12 isdiagrammatically illustrated in FIG. 3 of the drawings. In FIG. 3, aparticular form of disc construction is illustrated. However, it will beunderstood from the description of FIGS 6 to 12 that various forms ofdisc may be employed. In the embodiment illustrated in FIG. 6, the disc56 has semi-circular recesses at the peripheral edge and twocircumferentially extending rows of passages 72 and 74 spaced radiallyinwardly of the disc. Similarly, the disc 57 has peripheral edgerecesses 70a and two rows of passages 72a and 74a. Each of the recesses70 and 70a and passages 72, 72a, 74 and 74a has a small inlet orificeand a large outlet orifice. In the discs illustrated in FIG. 3, each ofthe notches 70, 70a has a small diameter on the upstream side of thedisc 56 and on the downstream side of disc 57 respectively. Thepassageways 72 are likewise arranged such that the small orifice isalternately arranged on the upstream side and downstream side of each ofthe discs 56 and 57. The passages 54a are all arranged with the smallerorifice disposed at the upstream face of the discs 56 and 57respectively. The path of flow of gas through the housing 12 isillustrated by the flow arrows shown in FIG. 3. The gas enters the trap32 by way of the input passage 40 and passes through the trap todischarge into the housing to discharge into the housing through thepassage 36. The gas travels through the housing to discharge through theoutlet passage 38 into the trap 34. The humidified gas then dischargesfrom the trap 34 by way of the output passageway 42. While the gas is inthe chamber 44 and while the discs 56 and 57 are rotated in thedirection of the arrows A, the gas will tend to be drawn through thevarious passages 70, 70a, 72, 72a, 74 and 74a in the direction from thehigh pressure areas to the low pressure areas. It has been found that bytapering the passages in the manner previously described and alternatelyarranging the direction of the taper in adjacent circumferentialpassages, it is possible to create a significant turbulence within thenebulizing chamber without creating any substantial back pressure whichwould inhibit the passage of gas through the device 10 (nebulizer).While it has been found that at slow speeds, the form and arrangement ofthe passageways 70, 70a, 72, 72 a, 74,740 is not critical, neverthelessat high speeds it is desirable to provide a large number of saidpassageways through the discs 56 and 57 in order to prevent the creationof a back pressure in the throughput line leading to and from thenebulizer 10 which would prevent the supply of an adequate amount ofhumid gas or vapor.

FIG. 4 of the drawings illustrates a form of apparatus which would beused to supply an anaesthetic gas to a patient. The gas is stored in aconventional storing device diagrammatically illustrated at in FIG. 4.Gas from the storage device 80 passes to a proportional control valve82. The proportional control valve 82 is adapted to supply anypredetermined proportion of the in-coming gas through input line 85 tothe nebulizer device 10 and the by-pass line 84. The output from thenebulizer 10 passes by way of the line 86 to mingle with the gas in theby-pass line 84 and to pass to a facemask or other applicator device 88.Where a proportional control valve 82 is provided as shown in FIG. 4, itis possible to operate the nebulizer motor at a constant speed and tovary the degree of increase in relative humidity by adjusting theproportion of the gas flowing to the nebulizer in proportion to the gasby-passing the nebulizer.

A diagrammatic illustration of a section through a suitable proportioncontrol valve 82 is shown in FIG. 5 wherein the valve housing 90 has aninput passage 92 and output passages 94 communicating with the inputline 85 and 95 communicating with the by-pass line 84. The valve body 98which is rotatably mounted within the housing 90 has an intake chamber100 and an associated output passage 102. In the position shown in FIG.5, all of the drygas entering the valve by way of the passage 92 will bedirected to the nebulizer through the passages 102 and 94. To adjust thepercentage of gas being directed to the nebulizer, the valve body 98 isrotated so that any required portion of the output passage 96 is openedto permit gas to flow into the by-pass line 84. It will be seen that thevalve 82 may be rotated from the position shown in FIG. 5 to a positionwherein all of the dry gas entering the valve may be discharged throughthe output passage 96 into by-pass line 94.

Referring to FIG. 6 a disc 110 which is suitable for use with anebulizer of the present invention is illustrated in FIG. 6 of thedrawings. The disc has a central opening 112 adapted to be fitted overthe drive shaft 52 in a manner similar to the discs previouslydescribed. The disc 110 has a V-shaped groove 114 formed at theperipheral edge thereof. A plurality of small diameter passages 116extend through the thickness of the disc and open into the lower end ofthe V-shaped groove 114. The passages 116 are located at uniformlyspaced intervals at a predetermined radius from the axis of rotation. Asecond row of larger diameter passages 118 extend through the body ofthe disc and they are spaced radially inwardly from their passages 116.It has been found that a disc of this type may be used in the apparatuspreviously described to effectively nebulize water which is charged intoor contained within the chamber 44.

An alternative disc structure is shown in FIG. 7 of the drawings. Inthis embodiment the disc 120 has two circumferentially spaced rows ofthrough passages 126 and 128 and a series of circumferentially spacedsemicircular notches l24. Both the front face and back face of the discare recessed adjacent to the notches 124 and passages 126 and 128.Again, it has been found that a disc of this type will serve to nebulizewater contained in or entering the chamber of the nebulizer when rotatedat a sufficiently high speed.

FIG. 8 of the drawings illustrates a further form of disc 130 which hasnotches 134 and passages 136 and 138, all circumferentially spacedrelative to one another. In FIG. 8, all of the notches 134 and all ofthe passages 136 and 138 have a tapered recess 139 formed in the frontface 133 extending from front to back so that the opening at the backface of the disc is smaller than the opening at the front face of thedisc.

In FIG. 9 of the drawings, the disc again has notches 144 at theperipheral edge thereof and passages 146 and 148 disposed radiallyinwardly therefrom. In this embodiment, the notches 144 are alternatelyrecessed on the front face and the back face. Similarly, the passages146 alternately taper from the front face to the back face and from theback face to the front face.

All of the passages l48 decrease in diameter from the front face to theback face.

In FIG. 10 of the drawings, the notches 154 and the back face. Thepassages 166 and 168 are not tapered.

A simple form of disc is illustrated in FIG. 12. In this embodiment, thenotches 164 and passages 176 and 178 extend straight through the body ofthe disc and they are not tapered in any way. I

Various additional modifications may be made to any of the discs. Forexample, an additional circumferentially spaced series of passages maybe located radially inwardly of the innermost ring shown in FIGS.

- 9 through 12.

When this apparatus is used in medical or surgical applications, the drygas, which may be any one of the well known anaesthetic gasses such as 0He or anaesthetic agents as N or C0,, is delivered to the nebulizer byway of the proportional control valve 82. Water may either be chargedinto the sump 46 before the nebulizer is activated or it may be addedcontinuously or in droplet form by way of an input passage 62. It willbe understood that a combination of water stored in the sump and acontinuous or drip supply may be used. When the motor 16 is activated,the discs 56, 57, 110, 120, 130, 140, 150, 160, will be rotatably drivenwithin the housing 44. A lower segment of each of the discs is adaptedto pass through any liquid (water) 60, which is located in the sump 46.In this regard, it will be noted that only a very small clearance 49, isprovided between the outer peripheral edge of the discs and the innerface of the cylindrical wall 26. It has been found that using any of thediscs previously described it is possible to nebulize and transferapproximately 1.4 grams of water to oxygen passing through the chamberat a rate of 5 liters per minute when the chamber is initially filledwith 20 grams of distilled water. Very similar results have beenobtained with each of the disc structures illustrated in the drawings.

A plain disc (not shown) without any vent holes has been found to becapable of providing a relatively low increase in relative humidity.There may be advantage in the use of a plain disc structure inapplications wherein it is desirable to provide an apparatus in which itis not possible or desirable to increase the relative humidity of a gasabove the predetermined maximum. This structure is, however, notsuitable for use when it is necessary to effect a higher rate ofincrease in relative humidity of gas. The plain disc does not permit agas to pass freely through the chamber at a sufficiently high volume orspeed nor does it provide the sufficiently effective milling action ofthe discs through the liquid 60 to increase the humidity of a largevolume of gas passing through the chamber 44. The discs which are formedwith the holes such as those illustrated in FIGS. 6 to 12 are capable ofproviding a substantial in crease in the relative humidity of a gas andof permitting a substantial flow of a gas through the chamber. It hasbeen found that the conically shaped holes of FIGS. 7 through 10 act asa weak fan tending to increase the turbulence of the gas passing throughthe chamber 44 without substantially increasing the pressures within themilling chamber 44. This structure permits a very low fresh air (gas)circulation of the type commonly required in clinical .practice withoutthe need to provide a subsidiary circulating fan. Thus the fluid betweenthe disc and the chamber wall is sheared by the differential velocity ofthe fluid at these surfaces. This differential velocity is proportionalto the rotating speed of the disc. The milling action thereby createdhas been found to cause molecules or minute droplets of fluid such aswater to be dispersed into the atmosphere within the chamber and to beintermingled with the gas flowing therethrough.

It has been found that the amount ofliquid which can be put into a gasstream increases with the speed of rotation and the depth of liquid inthe chamber.

It will also be noted that the input passage for the gas is locatedadjacent to the axis of rotation of the disc. When the disc is rotatingthe centrifugal forces at work within the chamber tend to cause adecrease in pressure in the area of the chamber adjacent the axis ofrotation and consequently this action assists in the feeding of gas orair into the chamber.

A feature of the apparatus of the present invention which distinguishesit from the conventional room humidifiers is that the rotating discaction on the liquid within the chamber is in the form of a milling"action. It is this milling action which causes the mechanical rupture ofthe molecular binding forces in the fluid. The air or gas stream whichpasses through the chamber picks up the fine ruptured particles of theliquid and carries them away, thereby the relative humidity of the gasis increased very rapidly.

As previously indicated, it will be noted that only a very smallclearance 49 is provided between inner cylindrical surface 26 of thechamber and the outer surface of the rotating disc. As a result, waterwhich is located within the chamber will be picked up by the boundarylayer adhesion and swept into motion and by centrifugal forces; theliquid will be thrown between the disc and the wall. The liquid 60 atthe chamber wall 26 will tend to adhere to the chamber wall 26 whilenearby liquid is dragged circumferentially by the disc; at the discsurface, the liquid tends to move at approximately the speed of thedisc.

A number of tests have been carried out in order to illustrate theamount of liquid which can be nebulized by the embodiments of thepresent invention in a predetermined time period; In each of the firstfour tests two discs measuring 6 inches in diameter and one eighth of aninch in thickness were mounted on the shaft of the nebulizer and rotatedat 1,640 r.p.m. therein. The peripheral edge was formed with 30 recessesof the type illustrated in FIG. 8. The first ring of passages werearranged one between each of the edge recesses and numbered thirty inall. The second row of passages were arranged between every second pairof passages in the first row and radially inwardly thereof and numbered15 in all. The third row numbering 15 in all were located in a staggeredrelationship with respect to the second row.

TEST 1 The first test was carried out using 35 grams of distilled waterin the sump and test results were measured after 10 minutes. Oxygen waspassed through the device at a rate of 6 liters per minute and on anaverage of three such tests the amount of water picked up.by the oxygenwas found to be 5.4 grams which expressed in mg/liter amounts to about91 mg/liter. A further feature noted in these tests was that, whereasthe ambient temperature of the input gas was 76 F, the outputtemperature of the gas from the nebulizer increased to 88 F.

TEST 2 A further test was carried out with a disc which had a smalldiameter (i.e., 1.705 inches) such that no contact was made with waterin the sump 46. Oxygen, at a rate of 5 liters per minute was passedthrough the device 10 and at the beginning of the test the sump 46contained 5 grams of distilled water. After a period of 10 minutes theamount of liquid picked up .by the oxygen was found to be 0.26 grams.

TEST 3 ln test three a disc of the type illustrated in FIG. 12 wasrotated in the chamber in the range of 1,400 to 1,750 r.p.m. but precisemeasurementwas impossible. Oxygen was passed through the chamber at arate of 5 liters per minute and 5 grams of distilled water was in thesump. After 10 minutes 1.26 grams of water was transferred to theoxygen.

The above,tests were repeated with various gases and the results ofthese are set out below in Table I.

TABLE I Gas Water Pick-up (mg/liter) wherein;

gas A comprises N 0 4 liters/min. O 2 liters/min. Flouthane 1% gas 13comprises N 0 4 liters/min. O 2 liters/min. Penthrane 1% gas C comprisedN 0 6 liters/min. A number of additional tests were carried out underthe conditions set forth in Test 3 above and the results are given belowin Table II.

TABLE II Test No. Blade (Fig) H2O Pick-up From these tests it will beapparent that the humidity of the oxygen can be considerably increasedby passing it through the device of the present invention.

Referring to Test 1 it will be seen that the relative hu midity of theoxygen has been increased to about 400 percent. While charts showing themass of water yapor in saturated oxygen are. not available it has beenestablished that the saturation content of oxygen is substantially thesame as that for air. Accordingly the relative humidity of the output ofTest 1 has been determined as follows:

Relative Humidity (I000 W X 100/RTE) Where R Flow rate (liter/min.)T=Time (mins.) W= Moisture picked up (grams) E Mass of vapor insaturated oxygen at test temperature (76 F) Relative humidity of oxygen10 X 5.4)][6 X 10 X (22.8)]bl approx. 400% By way of further explanationthe relative humidity is determined generally according to the aboveformula. Where water vapor is in equilibrium over a body of water therelative humidity is said to be 100 percent. More particularly, however,the relative humidity is 100 percent at various temperatures and theamount of water vapor within any given gas can be determined fromstandard tables which are available in the art. Now the relativehumidity of 100 percent is achieved at any given temperature when theair is quiet and when the body of water with which that air is inequilibrium is also quiet. Now if the water is made turbulent as bywater being caused to be thrown off the surface of the body of water bya mechanical means,

the adjacent gas (air) is no longer quiet and becomes itself turbulent.The new turbulent equilibrium can be measured'as a relative humidityabove the 100 percent (i.e., the relative humidity for quiet gas andliquid in equilibrium. In reality this new turbulent gas (air) liquid(water) equilibrium is supersaturated with individual molecules ofliquid (water) vapor or an agglutination of such molecules, suchagglutination either being visible or invisible to the naked eye. In theabove tests the molecules of water vapor in the gas are invisible to thenaked eye.

The above explanation of how one achieves a relative humidity in excessof 100 percent should not be taken to assume that any of the above testsin face does achieve an equilibrium between turbulent gas and water.What certainly is achieved is a relative humidity higher than would beachieved between quiet gas and liquid in equilibrium. Now referring tothe invention further test results indicate that after 10 minutes ofoperation of 50 grams by weight of water placed in sump 46 and with adisc speed of 1,540 RPM and an oxygen gas flow at the rate of 6liters/minute, 6.2 grams of water had been lost and hence 103.3 mg. ofwater had been dispersed into each liter of oxygen passing through thedevice 10. Throughout this test the vapor temperature was 73 F.

Referring to FIGS. 13 and 2a, further embodiments of the invention areillustrated. The nebulizer 10' has a series of fixed baffles disposed inclose proximity to the rotating discs 56 and 57. For example, the baffiemay be in the form of lugs 200 projecting inwardly from the cylindricalwalls of the chamber 44, particularly in the upper portion thereof(above the axis driveshaft 52 of rotation of the discs). Further,referring to FIGS. 1

and 2, an additional baffle may be disposed between the discs 56 and 57as by plug 27 which has a sufficient extent to project through thecylindrical 26 wall and into the space between the discs 56 and 57.Preferably the baffles are to be located in close proximity to therotating blades (discs), for example, one-eighth inch (3 mm.) so as todisrupt the flow of liquid adjacent the surfaces of the rotating discs.In this embodiment any of the discs disclosed in the FIGS. 3, 6, 7, 8,9, 10, 11 and 12 may be used. I

These and other modifications of the present invention will be apparentto those skilled in the art without departing from the scope of theinvention.

lclaim:

l. A device for controllably increasing the relative humidity of a gascomprising, a body having a chamber with a sump in the lower portion,means for admitting water opening into said sump, disc means in saidchamber rotatable with a sector of its marginal edge in said sump, meansfor rotating said disc means at a speed which is sufficiently high tonebulize water within said chamber by the agitating action of therotating disc means so as to increase the relative humidity of a gaspassing through the chamber, said disc means extending substantiallyacross the entire flow passage and having a plurality of aperturesextending through the said body thereof and a plurality of substantiallyuniform recesses extending inwardly from the peripheral edge thereof atcircumferentially spaced intervals to permit gas to flow from one sideof said disc to the other by way of said apertures and recesses duringrotation, inlet means opening into said chamber for admitting gas tosaid chamber and outlet means opening out of said chamber forwithdrawing gas therefrom, said inlet and outlet means being disposed onopposite sides of said disc means.

2. A device as claimed in claim 1 wherein a first ring of uniformlycircumferentially spaced apertures is spaced inwardly from theperipheral edge of said disc.

3. A device as claimed in claim 2 wherein each of said apertures has aninlet orifice at one face of said disc and an outlet orifice at theother face of said disc, inlet orifice being substantially smaller thansaid outlet orifice.

4. A device as claimed in claim 2 where a second ring of uniformlycircumferentially spaced apertures is located radially inwardly of saidfirst ring of apertures.

5. A device as claimed in claim 4 wherein the outer peripheral edge ofsaid disc is formed with a segmented circumferentially extendingV-shaped groove extending radially inwardly a distance sufficient toopen into said first ring of apertures, said first ring of aperturesbeing substantially smaller than said second ring of apertures.

6. A device as claimed in claim 4 wherein each of said apertures has aninlet orifice and an outlet orifice, the inlet orifices of the aperturesarranged in said second ring all being disposed at one side of said discand the outlet orifices being disposed at the other side of said disc,the inlet and outlet orifices of each adjacent aperture in said firstring of apertures being disposed on opposite sides of said disc wherebythe flow of gas through one orifice in the first ring of orifices is ina direction opposite to the flow of gas through adjacent orifices in thefirst row of orifices.

7. A device as claimed in claim 6 wherein the outer peripheral edge ofsaid disc is formed with a segmented circumferentially extendingV-shaped groove extending radially inwardly a distance sufficient toopen into said first ring of apertures, said first ring of aperturesbeing substantially smaller than said second ring of apertures.

8. A device as claimed in claim 1 having at least two disc membersmounted for rotation in said chamber about a common axis of rotation,said discs being arranged in a spaced parallel relationship.

9. A device as claimed in claim 1 including feed water control means forcontrolling the flow of feed water to said sump to thereby control theamount by which the relative humidity of the gas is increased and speedcontrol means for controlling the rotational speed of said disc means tothereby control the increase in relative humidity of the gas passingthrough the chamber.

10. The device of claim l,wherein the rotating disc means is disposedessentially perpendicular to the gas flow.

11. A device as claimed in claim 10 having at least two disc membersmounted for rotation in said chamber about a common axis of rotation,said discs being arranged in a spaced parallel relationship.

12. The device as claimed in claim 1 including baffle means and liquidtrap means at said gas outlet means to prevent the passage of heavyparticles of liquid from the chamber said baffle means extending towithin close proximity of a rotating disc such that the flow of liquidadjacent to the surface of the rotating disc is disrupted.

13. A device as claimed in claim 12 wherein the baffle means extends towithin 3 millimeters of the surface of a rotating disc.

- CERTIFICATE OF CORRECTION Patent No. 3,711,071 Dated an ary 16, 1973 jNikodem N. Urbanowicz Inventor(s) v It is certified that error appearsin the aboveddentified patent and that said Letters Patent are herebycorrected as shown below:

On the cover Sheet insert [73] Assignee: Air and Health ScientificLimited, Ontario, Canada Signed and sealed this 8th day of October 1974.

(SEAL) Attest: I

McCOY M. GIBSON JR. v C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM po'wso (10'69) USCOMM-DC 60376-P69 U 5. GOVE RNMENTPRINTING OFFICE,

1. A device for controllably increasing the relative humidity of a gascomprising, a body having a chamber with a sump in the lower pOrtion,means for admitting water opening into said sump, disc means in saidchamber rotatable with a sector of its marginal edge in said sump, meansfor rotating said disc means at a speed which is sufficiently high tonebulize water within said chamber by the agitating action of therotating disc means so as to increase the relative humidity of a gaspassing through the chamber, said disc means extending substantiallyacross the entire flow passage and having a plurality of aperturesextending through the said body thereof and a plurality of substantiallyuniform recesses extending inwardly from the peripheral edge thereof atcircumferentially spaced intervals to permit gas to flow from one sideof said disc to the other by way of said apertures and recesses duringrotation, inlet means opening into said chamber for admitting gas tosaid chamber and outlet means opening out of said chamber forwithdrawing gas therefrom, said inlet and outlet means being disposed onopposite sides of said disc means.
 2. A device as claimed in claim 1wherein a first ring of uniformly circumferentially spaced apertures isspaced inwardly from the peripheral edge of said disc.
 3. A device asclaimed in claim 2 wherein each of said apertures has an inlet orificeat one face of said disc and an outlet orifice at the other face of saiddisc, inlet orifice being substantially smaller than said outletorifice.
 4. A device as claimed in claim 2 where a second ring ofuniformly circumferentially spaced apertures is located radiallyinwardly of said first ring of apertures.
 5. A device as claimed inclaim 4 wherein the outer peripheral edge of said disc is formed with asegmented circumferentially extending V-shaped groove extending radiallyinwardly a distance sufficient to open into said first ring ofapertures, said first ring of apertures being substantially smaller thansaid second ring of apertures.
 6. A device as claimed in claim 4 whereineach of said apertures has an inlet orifice and an outlet orifice, theinlet orifices of the apertures arranged in said second ring all beingdisposed at one side of said disc and the outlet orifices being disposedat the other side of said disc, the inlet and outlet orifices of eachadjacent aperture in said first ring of apertures being disposed onopposite sides of said disc whereby the flow of gas through one orificein the first ring of orifices is in a direction opposite to the flow ofgas through adjacent orifices in the first row of orifices.
 7. A deviceas claimed in claim 6 wherein the outer peripheral edge of said disc isformed with a segmented circumferentially extending V-shaped grooveextending radially inwardly a distance sufficient to open into saidfirst ring of apertures, said first ring of apertures beingsubstantially smaller than said second ring of apertures.
 8. A device asclaimed in claim 1 having at least two disc members mounted for rotationin said chamber about a common axis of rotation, said discs beingarranged in a spaced parallel relationship.
 9. A device as claimed inclaim 1 including feed water control means for controlling the flow offeed water to said sump to thereby control the amount by which therelative humidity of the gas is increased and speed control means forcontrolling the rotational speed of said disc means to thereby controlthe increase in relative humidity of the gas passing through thechamber.
 10. The device of claim 1, wherein the rotating disc means isdisposed essentially perpendicular to the gas flow.
 11. A device asclaimed in claim 10 having at least two disc members mounted forrotation in said chamber about a common axis of rotation, said discsbeing arranged in a spaced parallel relationship.
 12. The device asclaimed in claim 1 including baffle means and liquid trap means at saidgas outlet means to prevent the passage of heavy particles of liquidfrom the chamber said baffle means extending to within close proximityof a rotating disc such that the fLow of liquid adjacent to the surfaceof the rotating disc is disrupted.
 13. A device as claimed in claim 12wherein the baffle means extends to within 3 millimeters of the surfaceof a rotating disc.